Injector apparatus and reheat combustor

ABSTRACT

Aspects of the present disclosure provide an apparatus including: an injector in fluid communication with an aft section of a reheat combustor in a power generation system, the aft section being positioned downstream of a combustion reaction zone in the reheat combustor, and positioned upstream of a turbine stage of the power generation system, wherein the turbine stage includes a turbine nozzle and a turbine blade row; and a conduit in fluid communication with the injector, wherein the conduit delivers at least one of a fuel from a fuel supply line and a carrier gas to the injector.

BACKGROUND OF THE INVENTION

The disclosure relates generally to injector apparatuses and reheatcombustors for fuel and air. More specifically, the disclosure relatesto reheat combustors and injectors for fuel and air which modify theperformance and output of a power generation system, such as a gasturbine system or turbomachine.

Turbine systems are frequently used to generate power for, e.g.,electric generators. A working fluid such as hot gas or steam can flowacross sets of turbine blades, mechanically coupled to a rotor of theturbine system. The force of the working fluid on the blades causesthose blades (and the coupled body of the rotor) to rotate. In manycases, the rotor body is coupled to the drive shaft of a dynamoelectricmachine such as an electric generator. In this sense, initiatingrotation of the turbine rotor can also rotate the drive shaft in theelectric generator to generate an electrical current and a particularpower output.

To generate the working fluid in a combustion-based turbomachine, a fuelcan combust within a combustor and in the presence of oxygen to generatea hot gas stream for actuating the blades of the turbine system. In somesystems, a portion of the air may not react in the combustor, and maycontinue downstream through the gas turbine system. To improve the poweroutput and efficiency of the turbomachine, this unreacted air can enteranother combustor known as a reheat combustor. In the reheat combustor,the unreacted air can combust in the presence of additional fuel togenerate more hot gas and actuate a latter turbine stage of theturbomachine. This type of turbomachine is known in the art as a reheatturbine.

A reheat turbine has the potential to attain greater efficiencies thanwhat is currently known in the art. The efficiency of existing combinedcycle plants, which can include reheat turbines, may be limited by theoutput and/or efficiency of the reheat combustor. In particular,designing the reheat combustor to have a different outlet temperaturefrom that of the first combustor can influence power output (e.g., byincreasing or decreasing the amount of fuel and combustion energy in thereheat combustor), and emissions (e.g., by combustion reactions in thereheat combustor outputting different amounts of carbon monoxide (CO),carbon dioxide, (CO₂) in addition to nitrogen oxide or nitrogen dioxide,known collectively as “NO_(x)”).

BRIEF DESCRIPTION OF THE INVENTION

Embodiments of the present disclosure provide injector apparatuses foruse in a power generation system, and reheat combustors which mayinclude one of the injector apparatuses. Generally, embodiments of thepresent disclosure can improve the performance of a combustion-basedpower generation system by providing additional fuel and air to adownstream area (also known as an “aft section”) of a combustionchamber. Diverting a portion of fuel to the injector can increase theamount of combustion reactions occurring within a reheat combustor,reduce the temperature of fluids entering the aft section, and reduceemissions outputs from the reaction chamber. The additional combustionreactions can occur in a preferred region of the chamber downstream ofrelatively heat-sensitive components, based on the location andtechnical configuration of the injecting apparatuses and/or reheatcombustor components.

A first aspect of the present disclosure provides an apparatusincluding: an injector in fluid communication with an aft section of areheat combustor in a power generation system, the aft section beingpositioned downstream of a combustion reaction zone in the reheatcombustor, and positioned upstream of a turbine stage of the powergeneration system, wherein the turbine stage includes a turbine nozzleand a turbine blade row; and a conduit in fluid communication with theinjector, wherein the conduit delivers at least one of a fuel from afuel supply line and a carrier gas to the injector.

A second aspect of the present disclosure provides an apparatusincluding: an injector located on a surface of a turbine nozzle of aturbine stage positioned downstream of a reheat combustor, wherein theturbine stage includes the turbine nozzle and a turbine blade row; and aconduit in fluid communication with the injector, wherein the conduitdelivers at least one of a fuel from a fuel supply line and a carriergas to the injector.

A third aspect of the present disclosure provides a reheat combustorincluding: a reaction chamber positioned between a mixing duct and aturbine nozzle separating the reaction chamber from a turbine stage ofthe power generation system, wherein the reaction chamber includes afore section and an aft section, the fore section including a combustionreaction zone from fuel supplied to the reheat combustor from a separatefuel supply line, and wherein an air and a fuel passing through themixing duct combust in the fore section of the reaction chamber; and aninjector located on a surface of one of a wall of the reaction chamberand a surface of the turbine nozzle, wherein the injector delivers atleast one of a carrier gas and a portion of the fuel from a fuel supplyline to the aft section of reaction chamber.

A fourth aspect of the present disclosure provides an apparatusincluding: a first injector located on a surface of a turbine nozzle ofa turbine stage positioned downstream of a reheat combustor, wherein theturbine stage includes the turbine nozzle and a turbine blade row; asecond injector located on a wall of the reheat combustor; and at leastone conduit in fluid communication with each of the first injector andthe second injector, wherein the at least one conduit delivers at leastone of a fuel from a fuel supply line and a carrier gas to an aftsection of the reheat combustor through at least one of the firstinjector and the second injector, and wherein the aft section ispositioned downstream of a combustion reaction zone in the reheatcombustor.

A fifth aspect of the present disclosure provides a reheat combustorincluding: a reaction chamber positioned between a mixing duct and aturbine nozzle of a turbine stage positioned downstream of the reactionchamber, the turbine stage including the turbine nozzle and a turbineblade row, wherein the reaction chamber includes a fore section and anaft section, and wherein an air and a first portion of a fuel passingthrough the mixing duct combust in the fore section of the reactionchamber; a first injector positioned on a surface of the turbine nozzle,wherein the first injector delivers a first portion of a carrier gas anda second portion of the fuel to the aft section of the reaction chamber;and a second injector extending through a wall of the reaction chamber,wherein the second injector delivers a second portion of the carrier gasand a third portion of the fuel to the aft section of the reactionchamber.

A sixth aspect of the present disclosure provides: a controlleroperatively connected to at least one valve positioned between a fuelsupply line and at least one injector for injecting a fuel and a carriergas into an aft section of a reheat combustor of a power generationsystem, wherein the aft section of the reheat combustor is positioneddownstream of a reaction zone within the reheat combustor; and a sensorin communication with the controller for determining one of an inlettemperature, an outlet temperature, and an emissions output of thereheat combustor; wherein the controller is configured to adjust aposition of the at least one valve based on one of the inlettemperature, the outlet temperature, and the emissions output of thereheat combustor.

A seventh aspect of the present disclosure provides: a reaction chamberpositioned between a first turbine stage of a power generation systemand a turbine stage of the power generation system, wherein the turbinestage comprises a turbine nozzle and a turbine blade row; a plurality ofinjectors positioned on a wall of the reaction chamber; and a conduit influid communication with the plurality of injectors, wherein the conduitdelivers at least one of fuel from a fuel supply line and a carrier gasto the reaction chamber through the plurality of injectors.

An eighth aspect of the present disclosure provides a reheat combustorincluding: a reaction chamber positioned between a first turbine stageof a power generation system and a turbine stage of the power generationsystem, wherein the turbine stage comprises a turbine nozzle and aturbine blade row; and a plurality of injectors for delivering at leastone of a fuel from a fuel supply line and a carrier gas to the reactionchamber, wherein each of the plurality of injectors is positioned on oneof a wall of the reaction chamber and a surface of the turbine nozzle inthe turbine stage.

A ninth aspect of the present disclosure provides a turbomachineincluding: a first stage combustor for reacting a fuel with a compressedair, wherein an unreacted portion of the compressed air passes through afirst turbine stage as an excess air; a reaction chamber for reactingthe fuel with the excess air in fluid communication with the firstturbine stage, and positioned between the first turbine stage and aturbine stage of the power generation system, wherein the turbine stagecomprises a turbine nozzle and a turbine blade row; a plurality ofinjectors positioned on one of the reaction chamber and a surface of theturbine nozzle; and a conduit in fluid communication with the pluralityof injectors for delivering at least one of a fuel and a carrier gas tothe reaction chamber, wherein a temperature of the reaction chambercauses the fuel, the excess air, and the carrier gas to combust andfully react within the reaction chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will be more readilyunderstood from the following detailed description of the variousaspects of the invention taken in conjunction with the accompanyingdrawings that depict various embodiments of the invention, in which:

FIG. 1 is a schematic view of a conventional gas turbine system whichincludes a reheat combustor.

FIG. 2 is a cross-sectional view of a conventional reheat combustor.

FIGS. 3-7 provide cross-sectional views of reheat combustors andapparatuses according to embodiments of the present disclosure.

FIG. 8 provides a schematic view of a turbomachine according toembodiments of the present disclosure.

FIG. 9 depicts an illustrative environment which includes a controllerinteracting with several sensors and valves according to embodiments ofthe present disclosure.

It is noted that the drawings of the invention are not necessarily toscale. The drawings are intended to depict only typical aspects of theinvention, and therefore should not be considered as limiting the scopeof the invention. In the drawings, like numbering represents likeelements between the drawings.

DETAILED DESCRIPTION OF THE INVENTION

As discussed herein, aspects of the invention relate generally toapparatuses for injecting fuel and air to a combustor of a powergeneration system, particularly a reheat combustor of a combustion-basedpower generation system such as a gas turbine. Apparatuses according tothe present disclosure can include, for example, an injector extendingthrough the surface of a turbine nozzle or the wall of a reheatcombustor. The injector can deliver fuel and/or air into an “aft”section of the reheat combustor, defined generally as a portion of thecombustor where combustion reactions do not occur without the injectionof additional fuel, e.g., at locations other than an inlet to the reheatcombustor. The turbine nozzle throat section can separate the aftsection of the reheat combustor from a turbine stage of the powergeneration system. A conduit can be in fluid communication with theinjector, and may divert fuel from a fuel supply line into the injector.The same conduit or a different conduit can direct a carrier gas, suchas a cooling air or, a bleed air from a combustor, or other gasesincluding oxygen and/or inert gases (i.e., gases used for injectionand/or dilution of fuel), into the injector along with the fuel.

Referring to FIG. 1, a conventional power generation system 10 in theform of a turbomachine is shown. Embodiments of the present disclosurecan be adapted for use with power generation system 10 and/or can beintegrated into components thereof. Power generation system 10 is shownby example as being a combustion-based turbomachine assembly, thoughembodiments of the present disclosure can also be adapted for use withother types of combustion systems where applicable. In the setting ofcombustion-based turbomachines, a combustor 12, connected to a fuelsupply 14, is typically located between a compressor 16 and a highpressure (HP) gas turbine 18 of power generation system 10. Fuel supply14 can be fluidly connected to or otherwise in the form of one or morefuel nozzles coupled to combustor 12. In an embodiment, fuel supply 14can be fluidly connected to a group positioned circumferentially aboutcombustor 12 and/or other combustors of power generation system 10.Compressor 16 and HP gas turbine 18 can be mechanically coupled to eachother through a rotatable shaft 20. To increase power output and/orefficiency, power generation system 10 can also include a reheatcombustor 22 and a low pressure (LP) gas turbine 24 in fluidcommunication with the fluids output from HP gas turbine 18.

Air 26 flows sequentially through compressor 16, combustor 12, HP gasturbine 18, reheat combustor 22, and LP gas turbine 24. The compressionprovided from compressor 16 can also increase the temperature of air 26.Fuel supply 14 can provide fuel to combustor 12 and reheat combustor 22,which combusts in the presence of air 26 to yield a hot gas stream. Thehot gas stream from combustor 12 can enter HP gas turbine 18 to impartmechanical energy to rotatable shaft 20, e.g., by rotating a group ofturbine buckets, thereby delivering power back to compressor 16 and/orany loads (not shown) mechanically coupled to rotatable shaft 20.Similarly, fuel provided from fuel supply 14 to reheat combustor 22 cancombust in the presence of excess air delivered from gas turbine 18 toyield a hot gas stream to LP gas turbine 24, which can impart additionalmechanical energy to rotatable shaft 20, e.g., by rotating turbinebuckets within LP gas turbine 24. Power generation system 10 may be oneof several individual turbomachines controlled via the same operatorand/or may be part of a larger power generation system.

A carrier gas supply 28 can be in communication with combustor 12 and/orreheat combustor 22. To reduce the amount of air 26 diverted fromcompressor(s) 16 to particular sections of combustor 12 and/or reheatcombustor 22, a carrier gas supply 28 can be in fluid communication withcombustor 12 and/or reheat combustor 22. Carrier gas supply 28 cangenerally include any dedicated supply of carrier gas and/or any othercomponent or system from which carrier gas can be drawn or repurposed.In a specific example, carrier gas supply 28 can include a compressor influid communication with reheat combustor 22 and/or another component.Carrier gas supply 28 can be located within and/or integral to powergeneration system 10. In other embodiments, carrier gas supply 28 can beexternal to power generation system 10 as an external component or otherexternal source of carrier gas. Air 26 that otherwise would be used tocool particular components of power generation system 10 can thus berepurposed as a reactant with fuel injected to other areas of combustor12 and/or reheat combustor 22 according to embodiments of the presentdisclosure.

Turning to FIG. 2, a cross-sectional view of a conventional reheatcombustor 22 capable of being modified into, adapted for, or otherwiseused with embodiments of the present disclosure is shown. In operation,air 26 can flow into an inlet 30 to reheat combustor 22. Fuel 32provided from fuel supply 14 (FIG. 1) via, e.g., a fuel supply line 34can intermix within a mixing duct 36 of reheat combustor 22. The brokenlines shown in fuel supply 34 designate an indeterminate length. Air 26can be in the form of hot gas discharged from, e.g., HP gas turbine 18(FIG. 1) and can be mixed with fuel 32 in a particular fashion to reducethe amount of delay before autoignition occurs. The size and length ofmixing duct 36 can be chosen to provide a particular delay beforeautoignition, and a certain type of fuel/air composition beforecombustion occurs. Reheat combustor 22 can be maintained at atemperature sufficient for combustion reactions to occur therein, e.g.,at least approximately 1065° Celsius (C). As used herein, the term“approximately” in relation to a specified numerical value (includingpercentages of base numerical values) can include all values within tenpercentage points of (i.e., above or below) the specified numericalvalue or percentage, and/or all other values which cause no operationaldifference or substantial operational difference between the modifiedvalue and the enumerated value. The term approximately can also includeother specific values or ranges where specified herein.

The mixed air 26 and fuel 32 can combust in a reaction zone 38 of reheatcombustor 22 via a process known as autoignition. Autoignition generallyrefers to a combustion reaction which occurs without the use of a flameor spark located within or upstream relative to the area where reactionsoccur. Some excess unreacted air in reaction zone 38 can recirculateback to mixing duct 36 to trigger additional combustion reactions, whileother portions of unreacted air may continue to other downstreamcomponents discussed herein. Generally, the term “upstream” refers to areference path extending in the direction opposite to the resultantdirection in which fluids pass through power generation system 10 (FIG.1). The term “downstream” refers to a reference path extending in thesame direction as the resultant direction in which fluids pass throughpower generation system 10. Thus, fuel and air generally travel throughpower generation system 10 in a downstream direction during operation.Reheat combustor 22 can be divided into a fore section 40 and an aftsection 42 based on, e.g., where combustion reactions between air 26 andfuel 32 from fuel supply line 34 occur. Aft section 42 can be free ofcombustion reactions therein, except where additional fuel and carriergas is injected to aft section 42 according to embodiments of thepresent disclosure. In any case, at least one turbine nozzle 44 canseparate reheat combustor 22 from a turbine stage of power generationsystem 10 (FIG. 1) (e.g., LP gas turbine 24). Turbine nozzle 44 is shownin a generalized, simplified form and in embodiments can include acomplex geometry (e.g., channels within or outside components withairfoil-type geometries and/or dimensions) and/or can be in the form ofmultiple turbine nozzles 44 in fluid communication with the samecombustion chamber 22. Turbine nozzle 44 can include a reduced surfacearea at its downstream end, which can be known as a throat 46 of turbinenozzle 44. Fluids passing through throat 46 may increase in fluidvelocity before passing to a turbine stage downstream of reheatcombustor 22 (e.g., LP gas turbine 24). The reaction zone 38 may extendpast the end of the aft section 42 of the reheat combustor into theturbine nozzle 44, but may end upstream of the throat 46 of turbinenozzle 44.

Applicants have determined that the efficiency of a conventional reheatcombustor may be sub-optimal in particular deployments and/or underparticular conditions. In an optimized reheat cycle, the firingtemperature of both combustors 12, 22 (FIG. 1) would be approximatelyequal, while the heat released in combustor 12 would be approximatelytwice that of reheat combustor 22. The numerous operational and designconstraints (e.g., environmental losses, excess reactants, manufacturingtolerances, emissions and/or temperature requirements, etc.) can posedesign challenges to creating these conditions within reheat combustor22 during operation. In particular, applicants have determined that thetemperature of inlet 30 in reheat combustor 22 appears to constrain theentire operating cycle of power generation system 10 (FIG. 1). In anexample of a conventional power generation system 10, the temperature ofinlet 30 of reheat combustor 22 can be, e.g., approximately 925° C. Thistemperature can be related to variables such as, e.g., pressure dropacross reheat combustor 22 and the number of autoignition reactionstherein. The discharge temperature from reheat combustor 22 can beapproximately 1550° C., and may be constrained by emissions (e.g., CO orNO_(x)) and the residence time needed to achieve efficient combustionwith emissions below particular levels (e.g., maximum amounts of exhaustallowed under environmental regulations).

Embodiments of the present disclosure can modify these constraintsand/or improve performance by applying a late lean injection ofadditional fuel and/or air to a combustor at particular locations,thereby increasing properties such as the inlet temperature thereof. Asused herein, late lean injection generally refers to any injection offuel and/or air positioned downstream relative to inlet 30. Increasingthe temperature of inlet 30 can allow, e.g., firing temperature of thefirst stage (i.e., temperature at which combustion occurs withincombustor 12), to increase and thereby improve the efficiency of theentire cycle.

Turning to FIG. 3, an apparatus 50 and reheat combustor 52 according toembodiments of the present disclosure are shown. Apparatus 50 caninclude an injector 54 extending through a surface of turbine nozzle 44.Embodiments of apparatus 50 can include any currently known or laterdeveloped instrument for injecting a fluid. As examples, injector 54 canbe in the form of a top-feed, side-feed, and/or body injector with aparticular nozzle such as an expansion deflection (also known as“pintle”) nozzle, a disc nozzle, a ball nozzle, etc. In any case,injector 54 can be connected to and in fluid communication with aconduit 56 for diverting an amount of fuel 32 from fuel supply line 34.In addition, injector 54 can be in fluid communication with air 26 frominlet 30 through an air conduit 58 positioned between inlet 30 andinjector 54. Air conduit 58 can optionally be in fluid communicationwith carrier gas supply 28 to deliver carrier gas from a source otherthan inlet 30 to injector 54, such as a dedicated supply of carrier gaspositioned within or external to power generation system 10 (FIG. 1) orunreacted air from compressor 16 (FIG. 1). Carrier gas from carrier gassupply 28 can optionally be intermixed with excess air from inlet 30within air conduit 58.

Apparatus 50 can be dimensioned to provide specific operationalcharacteristics. A separation distance S₁ between injector 54 and throat46 may be sized to allow substantially all (e.g., at least approximately95% of) fuel 32 to ignite in reheat combustor 52 and fully react beforeflowing through throat 46 into downstream components, such as LP gasturbine 24 (FIG. 1). In an example embodiment, separation distance S₁can have a dimension of between approximately 2.0 centimeters andapproximately 20 centimeters. The flow of fluids in conduit 56 and airconduit 58 and/or the size of injector 54 can be controlled and/orselected such that a mass ratio of carrier gas to fuel (e.g., a mass ofinjected air and/or carrier gas divided by a mass of injected fuel 32)in injector 54 is between approximately one-to-one and approximatelyfive-to-one.

Injector 54 can be oriented in a particular direction, shown by examplein FIG. 3 as being oriented substantially in opposition to a flow offluids such as reactants and/or combusted reaction products throughreheat combustor 52 and turbine nozzle 44. As used herein, “inopposition” encompasses all orientations where at least some fuel and atleast some carrier gas from first injector 54 and fluids within and/orexiting reheat combustor 52 will collide with each other (e.g., withinturbine nozzle 44) before continuing to flow as an at least partiallyintermixed fluid. In one embodiment, injector 54 and the flow of fluids(e.g., air 26) through or from reheat combustor 52 can be directlyopposed along a particular linear direction, i.e., having opposite orapproximately opposite orientations, such that the angular orientationof injector 54 and the fluid flow through reheat combustor 52 differ byapproximately 180° (i.e., within approximately five degrees more or lessthan 180°). In another embodiment, injector 54 and a direction of fluidflow through reheat combustor 52 can be at least partially directed inopposing directions, i.e., with one fluid flow component vector in thesame direction as the other outlet along one axis, with anothercomponent vector in a different direction from the other outlet along adifferent axis. For example, a flow of fluid through reheat combustor 52can be in a substantially horizontal reference direction, while injector54 can be oriented at an angle relative to this fluid flow with amagnitude of no more than approximately (e.g., within five degrees of)45°. In the example of FIG. 3, injector 54 delivers fuel and carrier gasin a direction with a component vector oriented against the flow offluid through reheat combustor 52. Any number of possible relativeorientations between a flow of fluid through reheat combustor 52 andinjector 54 are contemplated in embodiments of the present disclosure,so long as at least a portion of the carrier gas and fuel collides,intermixes, and/or reacts with at least a portion of fluid travellingthrough reheat combustor 52.

To control the amount of fuel 32 provided from fuel supply line 34 toinjector 54, apparatus 50 can include a valve 60 positioned between fuelsupply line 34 and conduit 56. In some embodiments, valve 60 may beconfigured to divert at most approximately twenty percent of the totalfuel 32 in fuel supply line 34 to conduit 56. This proportion may allow,e.g., a majority of combustion reactions in reheat combustor 52 to occurwithin fore section 40, while the provided fuel can be used for asmaller number of combustion reactions occurring in aft section 42and/or turbine nozzle 44. Dynamic control over the amount of combustionreactions in aft reaction zone 38 from fuel and carrier gas of injector54, can be provided via a controller 64 operatively connected to valve60. Controller 64 can generally include any type of computing devicecapable of performing operations by way of a processing component (e.g.,a microprocessor) and as examples can include a computer, computerprocessor, electric and/or digital circuit, and/or a similar componentused for computing and processing electrical inputs. Example componentsand operative functions of controller 64 are discussed in detailelsewhere herein.

A sensor 66 can be in communication with controller 64 and can bepositioned, e.g., within inlet 30 to reheat combustor 52 or downstreamof reaction zone 38 therein. Sensor(s) 66 can be in the form of atemperature sensor and/or an emission sensor for evaluating atemperature or amount of emissions (such as NO_(x)) at a particularlocation. Sensor(s) 66 in the form of a temperature sensor can includethermometers, thermocouples (i.e., voltage devices indicating changes intemperature from changes in voltage), resistive temperature-sensingdevices (i.e., devices for evaluating temperature from changes inelectrical resistance), infrared sensors, expansion-based sensors (i.e.,sensors for deriving changes in temperature from the expansion orcontraction of a material such as a metal), and/or state-change sensors.Where one or more sensors 66 include temperature sensors, thetemperature of fluid(s) passing through the location of sensor(s) 66 canbe measured and/or converted into an electrical signal or input.Sensor(s) 66 in the form of emission sensors can include general-purposegas detectors, thermal conductivity detectors, calorimetric detectortubes, and/or similar devices for measuring the amount or concentrationof particular substances in a stream of fluid or sample of exhaust air.Example types of emissions measured with sensor(s) 66 can include, e.g.,nitrogen oxide and nitrogen dioxide (NO_(x)) and/or carbon monoxide(CO), and/or oxygen (O₂). In any case, the relevant emissions can bemeasured in terms of total weight or relative molecular weight (e.g.,moles of NO_(x) or CO per gram of total exhaust), and may be convertedinto an electrical signal or input to controller 64. Sensor(s) 66 mayalso detect or calculate parameters derived from algorithms that inferthe value of interest, e.g., temperature or gas composition, based onmeasurements at other locations within the gas turbine and mathematicalmodels of the physics of gas flow through the turbine, where thecalculations are performed in conjunction with controller 64. Here,sensor(s) 66 can include components for measuring variables related totemperature and processing components (e.g., computer software) forprediction and/or calculating values of temperature or other metricsbased on the related variables. In general, the term “determining” inthe context of sensor(s) 66 refers to the process of finding aparticular value by direct measurement, predictive modeling, derivationfrom related quantities, and/or other mathematical techniques formeasuring and/or finding a particular quantity.

Controller 64, by way of a mechanical coupling to valve 60, can adjust aposition of valve 60 based on inputs and/or signals provided fromsensor(s) 66. In an example embodiment, controller 64 can adjust aposition of valve 60 based on an inlet temperature of reheat combustor52 and/or emissions output from reheat combustor 52. The controlling ofvalve 60 can increase or decrease an amount of fuel 32 provided fromfuel supply line 34 into conduit 56. Controller 64 can include programcode installed by a user for relating one or more variables (e.g.,temperatures and/or emission outputs) to magnitudes of combustion and/orinputs (e.g., amounts of fuel or air to inject through injector 54) forincreasing or decreasing the amount of combustion within reheatcombustor 52 by a particular amount.

In an example embodiment, controller 64 can adjust valve 60 to divert,e.g., between approximately ten and approximately twenty percent of fuel32 from fuel supply line 34 to conduit 56, thereby adjusting thetolerance of reheat combustor 52 to higher temperatures at inlet 30.Specifically, reducing the amount of fuel 32 combusted in an upstreamcombustor (e.g., combustor 12 (FIG. 1)) can reduce the amount of fuelpresent in inlet 30 before mixing duct 36, and thus reduce thelikelihood of premature combustion reactions occurring therein.Controller 64 can control the percentage of fuel 32 provided from fuelsupply line 34 based on operating conditions detected with sensor(s) 66and/or the composition of fuel 32. In addition, controller 64 cancontrol a relative amount of fuel 32 delivered to reheat combustor 52instead of a different combustor (e.g., combustor 12) by way of a fuelsupply valve 68 operatively connected to and/or positioned within fuelsupply line 34. Controller 64 can control a total amount of fuel 32provided to reheat combustor 52, e.g., through fuel supply line 34 andconduit 56, by its operative connection to fuel supply valve 68.Although valve 60 and fuel supply valve 68 are shown by example in FIG.3 as being separate components, a three-way valve (not shown) may besubstituted for valve 60 and fuel supply valve 68 to perform the samefunctions. Other valves and groups of valves discussed herein forcontrolling relative amounts of fluid can also be replaced bymultidirectional valves (not shown) where applicable.

Turning to FIG. 4, another embodiment of reheat combustor 52 is shown.In contrast to FIG. 3, FIG. 4 shows reheat combustor 52 with injector 54in fluid communication with aft section 42 of reheat combustor 52. As isdescribed elsewhere herein, aft section 42 can be defined as a portionof reheat combustor 52 located downstream of reaction zone 38 wherecombustion does not occur without late lean injection. In the embodimentshown in FIG. 4, conduit 56 can communicate fuel 32 from fuel supplyline 34 to injector 54. In addition, air conduit 58 can provide fluidcommunication of air and/or carrier gas from inlet 30 and/or carrier gassupply 28 to injector 54. The various additions and/or modificationsdescribed elsewhere herein with respect to FIG. 3 (e.g., the placement,use, and/or operation of valve 60, controller 64, and sensors 66) yetnot specifically discussed with respect to FIG. 4 are useable and/oradaptable for all embodiments of apparatus 50 and reheat combustor 52.In addition, a separation distance S₂ between injector 54 in aft section42 of reheat combustor 52 can allow substantially all (e.g., at leastapproximately 95%) of fuel 32 to ignite and fully react within reheatcombustor 52 before reaching throat 46 of turbine nozzle 44. The flow offluids in conduit 56 and air conduit 58 and/or the size of injector 54can also allow a mass ratio of air to fuel in injector 54 to be betweenapproximately one-to-one and approximately five-to-one.

FIGS. 3 and 4, together, depict alternative embodiments of apparatus 50and reheat combustor 52 according to the present disclosure. In somesituations, a conventional reheat combustor 22 (FIGS. 1, 2) can bemachined, modified, retrofitted, and/or otherwise processed into reheatcombustor 52 with injector 54 installed therein, which can extendthrough a wall/surface of aft section 42 or turbine nozzle 44. In thisconfiguration, air 26 and fuel 32 injected via injector 54 can combustin aft section 42. The remainder of air 26 and fuel 32 introduced toreheat combustor 54, i.e., from fuel supply line 34, can combust in foresection 40. As is shown in FIG. 3, reaction zone 38 can be substantiallycontinuous reaction zone extending from fore section 40 of reheatcombustor 52, through aft section 42, and up to and/or including turbinenozzle 44 without crossing throat section 46. The additionalmodifications discussed herein with respect to apparatus 50 can also beapplied to reheat combustor 52 where desired (e.g., the placement, use,and/or operation of valve 60, controller 64, sensors 66). In any event,injector 54 of reheat combustor can be positioned within either aftsection 42 or turbine nozzle 44 to provide different amounts ofintermixing and/or additional combustion within reheat combustor 52.

Embodiments of apparatus 50 can alter the performance of powergeneration system 10 (FIG. 1) during operation. For instance, theinjection of fuel into reheat combustor 52 at aft section 42 can allowadditional fuel to be provided to earlier combustor stages (e.g.,combustor 12 (FIG. 1) because of a higher temperature tolerance at inlet30 of reheat combustor 52. The greater temperature tolerance at inlet 30can be based at least partially on the diversion of some fuel 32 intoinjector 54, thereby reducing the amount of fuel provided to inlet 30and the risk of premature combustion within inlet 30. In operation,turbine nozzle 44 can be cooled by way of carrier gas (e.g., fromcarrier gas supply 28) at a particular temperature (e.g., approximately315° C.), and this carrier gas can afterwards be mixed with fuel 32provided from fuel supply line 34 before entering injector 54. In anexample embodiment, this mixing can increase the temperature of inlet 30by approximately 140° C. to an elevated temperature of approximately1065° C. In addition, the flow of fuel to combustor 12 can increase byapproximately twenty percent which can represent, e.g., approximatelyten percent of the total fuel provided to power generation system 10.This portion of the total fuel can be provided from other combustorsusing valve 68. Conversely, the fuel provided to reheat combustor 52 istwenty percent lower than in a conventional assembly (representing,e.g., approximately ten percent of the total gas turbine fuel), causingreheat combustor 52 to become more tolerant of the increased temperatureof inlet 30.

Turning to FIG. 5, an apparatus 70 according to embodiments of thepresent disclosure is shown. Apparatus 70 can form at least part of areheat combustor 72. Several of the elements and/or components discussedherein with respect to apparatus 50 and reheat combustor 52 areadaptable and/or modifiable for use with apparatus 70 and reheatcombustor 72. Reheat combustor can be in the form of a reaction chamberpositioned between inlet 30 and turbine nozzle 44, and may be shaped,sized, etc., for a predetermined level of combustion to take placetherein. Apparatus 70 can include a first injector 74 extending througha surface of turbine nozzle 44. Apparatus 70 can also include a secondinjector 76 extending through a wall of reheat combustor 72. Conduit 56and air conduit 58 can each be in fluid communication with firstinjector 74 and second injector 76. Conduit 56 can deliver fuel 32 fromfuel supply line 34 to first and second injectors 74, 76. Air conduit 58can deliver air from inlet 30 and/or carrier gas supply 28 (e.g., in theform of unreacted air) to first and second injectors 74, 76. First andsecond injectors 74, 76 can deliver fuel 32 and air 26 to reheatcombustor 72 in any desired relative proportion. In an exampleembodiment, each injector 74, 76 can provide fuel 32 and air 26 toreheat combustor 72 in a mass ratio of approximately one (i.e., with thesame amounts and/or flow rates of fuel 32 and air 26). Reheat combustor72 can be separated into fore section 40 and aft section 42. Foresection 40 can be defined as a portion of reheat combustor 72 wherecombustion reactions from fuel 32 exiting fuel supply line 34 can occur,i.e., within reaction zone 38. Aft section 42 can be defined as aportion of reheat combustor 72 where combustion reactions from fuel andair exiting first and second injectors 74, 76 occur. Thus, aft section42 is positioned downstream of fore section 40 within reheat combustor72.

Apparatus 70 can include valve 60 positioned between fuel supply line 34and conduit 56. Apparatus 70 can also include fuel supply valve 68mechanically coupled to fuel supply line 34. Fuel supply valve 68 cancontrol an amount of fuel delivered to reheat combustor 72 and othercombustors (not shown). Valve 60 and/or fuel supply valve 68 can beoperatively connected to controller 64. Controller 64 can adjust theposition(s) of valve 60 and/or fuel supply valve 68 based on operationalcharacteristics of reheat combustor 72. These operationalcharacteristics can include, e.g., a temperature of inlet 30 and/or anemissions output (e.g., CO and/or NO_(x) levels) of reheat combustor 72determined with sensor(s) 66 in communication with controller 64.Controller 64 can increase the amount of fuel 32 provided to conduit 56based on emissions being below a predetermined threshold and/or thetemperature of inlet 30 being above a predetermined threshold. One ormore thresholds can be defined in controller 64 via user inputs and/ormathematical computations and can be stored, e.g., in a memory (notshown) of controller 64. In an embodiment, controller 64 can adjustvalve 60 and/or fuel supply valve 68 to divert at most approximatelytwenty percent of fuel 32 in fuel supply line 34 to conduit 56, and morespecifically can divert between approximately ten percent andapproximately twenty percent of the fuel in fuel supply line 34 toconduit 56.

Apparatus 70 can include a splitting valve 78 positioned between conduit56 and first and second injectors 74, 76, for controlling relativeproportions of fuel 32 and air 26 delivered to first and secondinjectors 74, 76. Controller 64 can adjust splitting valve 78 to providedifferent amounts of fuel 32 and air 26 to injectors 74, 76 based onoperational variables, e.g., temperatures of inlet 30 and/or emissionsoutputs as determined by sensor(s) 66. For example, providing fuel 32 tosecond injector 76 upstream of first injector 74 can create additionaland/or higher temperature combustion reactions because of the greaterproximity of injector 76 to reaction zone 38.

First and second injectors 74, 76, can each be separated from throat 46of nozzle 44 by corresponding first and second separation distances S₁,S₂. First separation distance S₁ can limit the combustion of fuel fromfirst injector 74 to reaction zone 38 before entering throat 46 ofturbine nozzle 44. Separation distance S₁ can be determined by, e.g.,predicting an amount of combustion and a corresponding reaction volumefor an anticipated rate of injection through first injector 74, andcreating separation distance S₁ with at least a predetermined value oflength based on this prediction. In an example embodiment, separationdistance S₁ can have a dimension of between approximately 2.0centimeters and approximately 20 centimeters. To further increaseintermixing of fuel 32 and air 26, first injector 74 and/or secondinjector 76 can protrude from the surface of turbine nozzle 44 and/orthe wall of reheat combustor 72 substantially in opposition to thedirection of fluid flow through reheat combustor 72. A generaldefinition of positions which constitute an injector 72, 74 being “inopposition” to a flow of fluid is provided elsewhere herein.

Embodiments of the present disclosure also provide systems forcontrolling the injection of fuel 32 and air 26 into a separatelymanufactured or existing reheat combustor 72. Embodiments of apparatus70 can include controller 64 operatively connected to valve 60, withvalve 60 being positioned between fuel supply line 34 and conduit 56 tofirst and/or second injector 74, 76. As is discussed elsewhere herein,valve 60 can control, e.g., an amount of air provided from fuel supplyline 34 into conduit 56. Controller 64 can be in communication withsensor(s) 66 for determining one or more operating conditions of reheatcombustor 72, such as a temperature of inlet 30 and/or an emissionsoutput from reheat combustor 72. Controller 64 can include a computersystem with instructions (e.g., algorithms, program code, look-uptables, etc.) for adjusting a position of valve 60 and/or othercomponents discussed herein (e.g., fuel supply valve 68, splitting valve78, and/or an air supply valve 80 discussed elsewhere herein) based onreadings from sensor(s) 66.

Embodiments of the present disclosure can also include splitting valve78 operatively connected to controller 64 for controlling a relativeamount of fuel 34 delivered to first injector 74 or second injector 76.A carrier gas control valve 80 can also be operatively connected tocontroller 64, and may be positioned between carrier gas supply 28 andair conduit 58. Carrier gas control valve 80 can control an amount ofair provided from carrier gas supply 28 and/or inlet 30 to first andsecond injectors 74, 76. In some embodiments, splitting valve 78 maycontrol the amount of air divided between first and second injectors 74,76, (i.e., first and second portions of air 26 and/or carrier gas fromcarrier gas supply 28) as an alternative or addition to dividing fuel 34between first and second injectors 74, 76. Controller 64 can adjust theposition of splitting valve 78 and/or carrier gas control valve 80 basedon operational characteristics of reheat combustor 72, e.g., atemperature of inlet 30 and/or emission outputs from reheat combustor 72determined with sensor(s) 66 in communication with controller 64.Although splitting valve 78 is shown by example in FIG. 5 as being asingle component, it is understood that valve 78 can be in the form oftwo separate valves for fuel 32 and air 26, each of which may bepositioned between injectors 74, 76 and conduit 56 or air conduit 58. Itis understood that embodiments of apparatuses 50, 70, reheat combustors52, 72, and/or components thereof can be mixed, modified, and/orotherwise applied to each other as desired and/or needed for particularapplications.

Referring briefly to FIG. 6, an alternative embodiment of apparatus 70and reheat combustor 72 is shown. Here, multiple conduits 56 and airconduits 58 can be fluidly connected to reheat combustor 72 throughfirst and second injectors 74, 76. In a specific example, as shown inFIG. 6, each injector 74, 76 can be fluidly connected to a respectiveconduit 56 and air conduit 58. Each conduit 56 and air conduit 58 mayalso include a corresponding splitting valve 78 for controlling portionsof fuel 32 and air 26 provided to each injector 74, 76. Further, in thisillustrative example, carrier gas control valve 80 is shown as athree-way valve for controlling portions of air 26 or carrier gasesprovided to each air conduit 58. It is understood that valve 60,splitting valve(s) 78, and carrier gas control valve 80 can be separatedinto multiple components and/or combined where desired and/orappropriate to a particular implementation.

The present disclosure contemplates additional equipment for improvingefficiency and otherwise augmenting the amount of power generated inpower generation system 10 (FIG. 1). Turning to FIG. 7, embodiments ofthe present disclosure can include an apparatus 90 which may be asubstitute for reheat combustor 22 (FIG. 2) in a conventional powergeneration system. Apparatus 90 can be in the form of an alternativereheat combustor with a reaction chamber 92 therein, and can besubstituted for one or more conventional reheat combustors 22 of powergeneration system 10 (FIG. 1). Where desired, embodiments of apparatus90 can also be used in combination with and/or as a substitute forreheat combustors 52, 72 (FIGS. 3-6). Apparatus 90 can be free of mixingducts 36 (FIGS. 3-6) positioned between inlet 30 and reaction chamber92.

Apparatus 90 can include a plurality of injectors 94 extending through awall of reaction chamber 92, and/or additional injectors 94 extendingthrough turbine nozzle 44. As is discussed elsewhere herein, turbinenozzle 44 can separate reaction chamber 92 from a second turbine stage(e.g., LP gas turbine 24 (FIG. 1)) of a particular power generationsystem. Injectors 94 can be in the form of any currently known or laterdeveloped component for injecting air 26 and/or fuel 32, and asnon-limiting examples, one or more injectors 94 can be in the form of“rake” style immersion injectors, nozzle injectors, air blast fuelinjectors, pressure-atomizing injectors, premix injectors, and/orprevaporizing injectors. Injectors 94 can be oriented substantially inopposition to a flow of a fluid (e.g., air 26) through reaction chamber92, such that intermixing of fuel and air with the fluid(s) flowingthrough apparatus 90 increases. In an example embodiment, the ratio offuel to carrier gas in each one of injectors 94 can be, e.g.,approximately one-to-one, or can vary from this amount based on aposition and/or desired value or range of values for the operatingcharacteristics of apparatus 90. In any event, fuel 32 injected toapparatus 90 through injectors 94 can make up the entirety of fuel 32injected to apparatus 90, without a primary fuel supply line (e.g., fuelsupply line 34) being in direct fluid communication with reactionchamber 92 of apparatus 90.

The use of multiple injectors 94 can reduce or altogether eliminate thepresence of mixing duct 36 (FIGS. 2-6) between inlet 30 and reactionchamber 92. Where reaction chamber 92 is approximately the same lengthas reheat combustors 22, 52, 72, the addition of injectors 94 andabsence of mixing duct 36 may change the amount of temperature and/ortime needed for of fuel 32 and air 26 to combust therein. In anembodiment, fuel 32 can combust within reaction chamber 92 less thanapproximately one millisecond after exiting a particular injector 94. Ithas been discovered that this change in reaction conditions can allow agreater amount of air 26 and fuel 32 to react, a more complete burnoutof emissions such as carbon monoxide (CO), and reduction in the overallreaction temperature throughout reaction chamber 92. These changes tothe reaction conditions are, in part, due to the reduced amounts of fuel32 provided by each injector 94 along the length of reaction chamber 92and nozzle 44. The more complete combustion of reactants in apparatus90, as compared to conventional reheat combustors 22, can also limitproduction of NO_(x) emissions. This change in reaction conditions canalso increase the tolerance for increased temperatures at inlet 30,further reducing pressure loss across apparatus 90 (i.e., between inlet30 and turbine nozzle 44) because apparatus 90 is free of mixing zones,and accommodates combustion throughout reaction chamber 92 without theuse of dedicated mixing zones and/or ducts.

Apparatus 90 can optionally include other components and featuresdiscussed elsewhere herein as components of apparatuses 50, 70 or reheatcombustors 52, 72 where desired and/or applicable. For example,apparatus 90 can include a valve 98 positioned between fuel supply line34 and conduit 56 to injectors 94. Fuel supply line 34 can deliver mostof fuel 32 therein (e.g., at least two-thirds of a total fluid flow) toanother combustor independent from apparatus 90, e.g., combustor 12(FIG. 1). Valve 98 can divert a portion of fuel 32 in fuel supply line34 to conduit 56 and injectors 94 to initiate combustion reactionswithin reaction chamber 92 of apparatus 90. In an example embodiment,valve 98 can be sized to divert up to one third of the total flow offuel 32 in fuel supply line 34 to injectors 94.

To further control the amount of fuel 32 provided to injectors 94,apparatus 90 can also include controller 64 operatively connected tovalve 98. Sensor(s) 66 can also be in communication with controller 64to determine a temperature of inlet 40, an outlet temperature (i.e., atemperature within or beyond turbine nozzle 44) and/or an emissionsoutput from reaction chamber 92. Controller 64 can be configured toadjust the position of (i.e., open or close) valve 98 by use of programcode and/or software provided therein and with reference to valuesdetermined with sensor(s) 66. For example, as discussed elsewhereherein, controller 64 can close valve 98 to reduce the amount of fuel 32provided to apparatus 90 in response to emission outputs determined withsensor(s) 66 being too high, open valve 98 based on a temperature ofinlet 30 being greater than a threshold value, and/or otherwise adjustthe position of valve 98 based on operational conditions of apparatus 90determined with sensor(s) 66.

Turning to FIGS. 7 and 8 together, embodiments of the present disclosurecan provide a turbomachine 100 adapted to include apparatus 90 therein.Turbomachine 100 can include combustor 12 in the form of a first stagecombustor for receiving fuel from fuel supply 14 via fuel supply line34. Combustor 12 can also be in fluid communication with compressor 16and/or carrier gas supply 28 to receive air which reacts with fuel fromfuel supply 14. Apparatus 90 can be positioned between HP gas turbine 18and LP gas turbine 24, thereby causing reaction chamber 92 therein to bein fluid communication with an upstream turbine stage and a downstreamturbine stage (e.g., HP gas turbine 18 (upstream) and LP gas turbine 24(downstream)). Conduit 56 can deliver fuel 32, which may be intermixedwith air 26 drawn from inlet 30, to reaction chamber 92. The temperaturewithin reaction chamber 92 may cause combustion reactions to occurtherein. At least some fuel 32 can react with excess portions of air 26yielded from the upstream turbine stage (e.g., HP gas turbine 18), whichmay be in the form of air from compressor 12 and/or carrier gasdelivered from carrier gas supply 28. In an embodiment, fuel enteringreaction chamber 92 from conduit 56 and injectors 94 can combust lessthan approximately one millisecond after entering reaction chamber 92.

As discussed elsewhere herein, turbomachine 100 can include valve 98operatively connected to conduit 56 for controlling a magnitude of fuel32 delivered to injectors 94 from fuel supply line 34. Valve 98, morespecifically, can control a relative quantity of fuel provided from fuelsupply line 34. The amount of fuel 32 provided with valve 98 can belimited by, e.g., a physical limit on valve 98 (maximum positions ofopenness and/or closure), a user-determined maximum value stored incontroller 64 and applied to the adjusting of valve 98, and/orcombinations of these techniques and other techniques. In an exampleembodiment, valve 98 can divert up to approximately one third of thefuel 32 within fuel supply line 34 into conduit 56. The position ofvalve 98 and the amount of fuel 32 provided into conduit 56 can becontrolled by, e.g., controller 64 coupled to valve 98. Controller 64can adjust the position of valve 98 based on, e.g., values determinedwith sensor(s) 66 in communication with controller 64. The otherfeatures discussed herein with regard to apparatus 90 can also beapplied to turbomachine 100 where desired. As examples, and as shown inFIG. 7, injectors 94 may be oriented substantially in opposition to aflow of a fluid through reaction chamber 92, and/or injectors 94 caninject carrier gas and fuel into reaction chamber 92 in a ratio ofapproximately one-to-one.

The allocation of fuel between combustor 12 and apparatus 90 can be setand adjusted using controller 64 based on the current and/or desiredoperating conditions of turbomachine 100, and the composition of aparticular fuel 32 to be combusted. For instance, combustor 12 ofturbomachine 100 can be allocated approximately two-thirds of the totalfuel in fuel supply 14, and the temperature at inlet 30 of apparatus 90can be, e.g., approximately 1340° C. to provide a shortened autoignitiondelay time (e.g., less than approximately 0.5 milliseconds). In anotherexample, the operating temperatures of combustor 12 and apparatus 90within turbomachine 100 may be approximately equal to each other. Theallocation of fuel from fuel supply 14 between combustor 12 andapparatus 90 can determine, e.g., the firing temperature within eachstage. In addition, a total amount of carrier gas provided to combustor12 and apparatus 90 can be chosen to maintain a predetermined a gasturbine exhaust temperature and this amount of carrier gas can becontinuously and/or periodically adjusted via controller 64. Othervariables affected by the amount and allocation of fuel 32 and carriergas 26 can include: emissions from turbomachine 100, total fuel intake,and tolerance ranges for the temperature of inlet 30.

FIG. 9 depicts an illustrative environment 100 in communication withsensor(s) 66 for controlling one or more valve(s) 60, fuel supplyvalve(s) 68, splitting valve (s) 78, carrier gas control valve(s) 80,and/or valve(s) 98 (collectively, “valve(s)”) according to embodiments.To this extent, environment 100 includes controller 64 for performingprocesses and imparting electrical commands to control valve(s) 60, 68,78, 80, 98 and associated systems and tools. Although each type of valve60, 68, 78, 80, 98 discussed herein is shown by example in FIG. 9, it isunderstood that environment 100 with controller 64 can be used with onlyone or multiple embodiments of the present disclosure discussed herein,including without limitation one or more reheat combustors 52, 72 (FIGS.3-6) and/or apparatuses 50, 70, 90 (FIGS. 3-8). Controller 64 is shownas including a valve control system 112, which makes controller 64operable to direct and operate valve(s) 60, 68, 78, 80, 98 andassociated systems and tools described herein and implement any/all ofthe embodiments described herein. In operation, valve control system 112can issue electrical commands, which in turn may be converted intomechanical actions (e.g., an action of opening and closing one or morevalves 60, 68, 78, 80, 98) in response to particular conditions. Theconditions for opening and/or closing valves 60, 68, 78, 80, 98 caninclude, e.g., a temperature of inlet 30 (FIGS. 2-7) or an emissionoutput from turbine nozzle 44 (FIGS. 2-7) being within or outside arange of threshold values, or other operating variables and/or valuesdetermined with sensor(s) 66 being within or outside a particular rangeof threshold values.

Controller 64 is shown including a processing component 104 (e.g., oneor more processors), a memory 106 (e.g., a storage hierarchy), aninput/output (I/O) component 108 (e.g., one or more I/O interfacesand/or devices), and a communications pathway 110. In general,processing component 104 executes program code, such as valve controlsystem 112, which is at least partially fixed in memory 106. Whileexecuting program code, processing component 104 can process data, whichcan result in reading and/or writing transformed data from/to memory 106and/or I/O component 108 for further processing. Pathway 110 provides acommunications link between each of the components in controller 64. I/Ocomponent 108 can comprise one or more human I/O devices, which enable ahuman or system user 114 to interact with the controller 64 and/or oneor more communications devices to enable user(s) 114 to communicate withthe controller 64 using any type of communications link. To this extent,valve control system 112 can manage a set of interfaces (e.g., graphicaluser interface(s), application program interface, etc.) that enableuser(s) 112 to interact with valve control system 112. Further, valvecontrol system 112 can manage (e.g., store, retrieve, create,manipulate, organize, present, etc.) data, such as system data 116(including measured or recorded temperatures, emission outputs, etc.)using any solution.

In any event, controller 64 can comprise one or more general-purpose orspecific-purpose computing articles of manufacture (e.g., computingdevices) capable of executing program code, such as valve control system112, installed thereon. As used herein, it is understood that “programcode” means any collection of instructions, in any language, code ornotation, that cause a computing device having an information processingcapability to perform a particular function either directly or after anycombination of the following: (a) conversion to another language, codeor notation; (b) reproduction in a different material form; and/or (c)decompression. To this extent, the valve control system 112 can beembodied as any combination of system software and/or applicationsoftware.

Further, the valve control system 112 can be implemented using a set ofmodules 118. In this case, a module 118 can enable the controller 64 toperform a set of tasks used by valve control system 112, and can beseparately developed and/or implemented apart from other portions ofvalve control system 112. Controller 64 can also include a userinterface module 120 for displaying (e.g., via graphics, text, and/orcombinations thereof) a particular user interface on a display componentsuch as a monitor. When fixed in memory 106 of controller 64 thatincludes a processing component 104, a module is a substantial portionof a component that implements the functionality. Regardless, it isunderstood that two or more components, modules and/or systems may sharesome/all of their respective hardware and/or software. Further, it isunderstood that some of the functionality discussed herein may not beimplemented or additional functionality may be included as part ofcontroller 64.

When controller 64 comprises multiple computing devices, each computingdevice may have only a portion of valve control system 112 fixed thereon(e.g., one or more modules 118). However, it is understood thatcontroller 64 and valve control system 112 are only representative ofvarious possible equivalent computer systems that may perform a processdescribed herein. To this extent, in other embodiments, thefunctionality provided by controller 64 and valve control system 112 canbe at least partially implemented by one or more computing devices thatinclude any combination of general and/or specific purpose hardware withor without program code. In each embodiment, the hardware and programcode, if included, can be created using standard engineering andprogramming techniques, respectively.

Regardless, when controller 64 includes multiple computing devices, thecomputing devices can communicate over any type of communications link.Further, while performing a process described herein, controller 64 cancommunicate with one or more other computer systems using any type ofcommunications link. In either case, the communications link cancomprise any combination of various types of wired and/or wirelesslinks; comprise any combination of one or more types of networks; and/oruse any combination of various types of transmission techniques andprotocols.

It is understood that aspects of the invention further provide variousalternative embodiments. For example, in one embodiment, the presentdisclosure provides a controller for adjusting an amount of fuel and/orair provided to components of reheat combustors 52, 72 (FIGS. 3-6)and/or apparatuses 50, 70, 90 (FIGS. 3-7) by adjusting the position ofvalve(s) 60, 68, 78, 80, 98. In other embodiments, using reheatcombustors 52, 72, and/or apparatus 90 can include operating controller64 manually (e.g., by a technician) or by the intervention of one ormore computer systems operatively connected thereto. It is understoodthat controller 64 may serve technical purposes in other settings beyondgeneral operation, including without limitation: inspection,maintenance, repair, replacement, testing, etc.

Valve control system 112 can be in the form of a computer program fixedin at least one computer-readable medium, which when executed, enablescontroller 64 to operate and adjust the position of valve(s) 60, 68, 78,80, 98. To this extent, the computer-readable medium includes programcode which implements some or all of the processes and/or embodimentsdescribed herein. It is understood that the term “computer-readablemedium” comprises one or more of any type of tangible medium ofexpression, now known or later developed, from which a copy of theprogram code can be perceived, reproduced or otherwise communicated by acomputing device. For example, the computer-readable medium cancomprise: one or more portable storage articles of manufacture; one ormore memory/storage components of a computing device; paper; etc.

The apparatus and method of the present disclosure is not limited to anyone particular gas turbine, combustion system, internal combustionengine, power generation system or other system, and may be used withother power generation systems and/or systems (e.g., combined cycle,simple cycle, nuclear reactor, etc.). Additionally, the apparatus of thepresent invention may be used with other systems not described hereinthat may benefit from the increased operational range, efficiency,durability and reliability of the apparatus described herein. Technicaleffects of the present disclosure can include, without limitation, theability to increase, decrease, or otherwise adjust the inlettemperatures and amounts of combustion in combustors and reheatcombustors of a power generation system, e.g., by adjusting the amountof fuel and carrier gas allocated between different combustors andportions of the same combustor.

Embodiments of the present disclosure can provide several technical andcommercial advantages. As one example, embodiments of the presentdisclosure can be provided as modifications or retrofitted components toexisting gas turbine systems. Combining embodiments of the presentdisclosure with conventional power generation systems and/or componentsthereof can allow a greater fraction of the total gas turbine fuel flowto be provided to a first stage combustor, with a lower burden on anyreheat combustors in the system and greater operational efficiency. Inaddition, the various embodiments discussed herein can permit a firststage combustor to combust fuel at a higher temperature, because thestaged combustion reactions in a downstream reheat combustor can bestaged in multiple reaction zones as discussed herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

This written description uses examples to disclose the invention,including the best mode, and to enable any person skilled in the art topractice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

1. An apparatus comprising: a reheat combustor in a power generationsystem; an injector embedded within a surface of the reheat combustorand in fluid communication with an aft section of the reheat combustor,the aft section being positioned downstream of a combustion reactionzone in the reheat combustor, and positioned upstream of a turbinenozzle of the power generation system; and a conduit in fluidcommunication with the injector, wherein the conduit delivers at leastone of a fuel and a carrier gas to the injector.
 2. The apparatus ofclaim 1, further comprising at least one valve positioned between a fuelsupply line and the conduit for controlling an amount of the fueldelivered from the fuel supply line to the injector.
 3. The apparatus ofclaim 2, wherein the fuel supply line is in fluid communication with amixing duct of the reheat combustor, and the at least one valve divertsat most approximately thirty percent of the fuel from the fuel supplyline to the injector.
 4. The apparatus of claim 2, further comprising: acontroller operatively connected to the at least one valve; and a sensorin communication with the controller for determining one of an inlettemperature of the reheat combustor, an outlet temperature of the reheatcombustor, and an emissions output of the reheat combustor; wherein thecontroller is configured to adjust a position of the at least one valvebased on one of the inlet temperature of the reheat combustor, theoutlet temperature of the reheat combustor, and the emissions output ofthe reheat combustor.
 5. The apparatus of claim 1, wherein a separationdistance between the injector and a throat section of the turbine nozzleallows the fuel to ignite and react within the reheat combustor beforeentering a throat section of the turbine nozzle.
 6. The apparatus ofclaim 1, wherein the conduit delivers the fuel and the carrier gas tothe injector.
 7. The apparatus of claim 6, wherein a mass ratio of thecarrier gas to the fuel in the injector is between approximatelyone-to-one and approximately five-to-one.
 8. An apparatus comprising: aturbine nozzle positioned downstream of a reheat combustor; an injectorlocated embedded within a surface of the turbine nozzle; and a conduitin fluid communication with the injector, wherein the conduit deliversat least one of a fuel and a carrier gas to the injector.
 9. Theapparatus of claim 8, further comprising at least one valve between afuel supply line and the conduit for controlling an amount of the fuelprovided from the fuel supply line to the injector.
 10. The apparatus ofclaim 9, wherein the fuel supply line is in fluid communication with amixing duct positioned upstream of the turbine nozzle, and the at leastone valve diverts at most approximately thirty percent of the fuel fromthe fuel supply line to the injector.
 11. The apparatus of claim 9,further comprising: a controller operatively connected to the at leastone valve; and a sensor in communication with the controller fordetermining one of an inlet temperature of the reheat combustor, theoutlet temperature of the reheat combustor, and an emissions output ofthe reheat combustor; wherein the controller is configured to adjust aposition of the at least one valve based on one of the inlet temperatureof the reheat combustor, an outlet temperature of the reheat combustor,and the emissions output of the reheat combustor.
 12. The apparatus ofclaim 8, wherein a separation distance between the injector embeddedwithin the surface of the turbine nozzle and a throat section of theturbine nozzle causes the fuel to ignites and reacts before entering thethroat section of the turbine nozzle.
 13. The apparatus of claim 8,wherein the conduit delivers the fuel and the carrier gas to theinjector.
 14. The apparatus of claim 8, wherein the injector is orientedon the surface of the turbine nozzle substantially in opposition to adirection of a fluid flow against the turbine nozzle.
 15. A reheatcombustor comprising: a reaction chamber positioned downstream of amixing duct and upstream of a turbine nozzle of a power generationsystem, wherein the reaction chamber includes a fore section and an aftsection, and wherein an air and a first portion of a fuel delivered fromthe mixing duct combust in the fore section of the reaction chamber; andan injector embedded within a surface of one of a wall of the reactionchamber and the turbine nozzle, wherein the injector delivers at leastone of a carrier gas and a second portion of the fuel to the aft sectionof the reaction chamber.
 16. The reheat combustor of claim 15, furthercomprising: a conduit in fluid communication with the injector and afuel supply line, wherein the fuel supply line is further in fluidcommunication with the mixing duct; and at least one valve positionedbetween the fuel supply line and the conduit for controlling an amountof the second portion of the fuel provided from the fuel supply line tothe injector.
 17. The reheat combustor of claim 16, wherein the at leastone valve diverts at most approximately thirty percent of the fuel fromthe fuel supply line to the injector as the second portion of the fuel.18. The reheat combustor of claim 16, further comprising: a controlleroperatively connected to the at least one valve; and a sensor incommunication with the controller for determining one of an inlettemperature of the reaction chamber, an outlet temperature of thereaction chamber, and an emissions output of the reaction chamber;wherein the controller is configured to adjust a position of the atleast one valve based on one of the inlet temperature of the reactionchamber, the outlet temperature of the reaction chamber, and theemissions output of the reaction chamber.
 19. The reheat combustor ofclaim 15, wherein a separation distance between the injector embeddedwithin the turbine nozzle and a throat section of the turbine nozzleallows the fuel to ignites and reacts before entering the throat sectionof the turbine nozzle.
 20. The reheat combustor of claim 15, furthercomprising an air conduit in fluid communication with the injector andthe reaction chamber, wherein the air conduit delivers a carrier gas tothe injector, and the carrier gas comprises unreacted air from one of anexternal air supply and a combustor in fluid communication with thepower generation system.